Perhaps you should try some spelling variations:
tai thong » tai thuong, tai phong, tai trong
cua viet » ca viet, hoa viet, cua vat
cam thuc » am thuc, nam thuc, cam thu
hanh lam » thanh lap, hanh kem, hanh va
hieu van » hieu va, thien van, lieu va
sach tai » sach bai, sach tham, sach dao
su tien » su kien, su hien, tu tieng
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
hieu ve » hieu va
xay hoi » xa hoi, tay hoi, cay phoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tai thong xay hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh lam ((su tien) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tai thong xay hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh lam ((su tien) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tai thong xay hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh lam ((su tien) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: su sach tai thong xay hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh lam ((su tien) or (cua viet))*.